Adaptive assignment of elevator car calls

Abstract

At a single floor of a building, such as at the lobby, destination calls are entered via a destination call entry device touch pad such as a (12) so that overall system response can be optimized during up-peak service intervals. A maximum number of calls are assigned to each car in order of its priority, or advantageous situation with respect to loading the lobby passengers, and the dispatch interval for each car is individually adjusted. The calls may be assigned to a car prior to its arrival at the lobby, and call assignments are audibly and/or visually displayed by an indicator device (16).

We claim: 
     
       1. An elevator system comprising two or more cars servicing a plurality of floors in a building and processor means controlling the motion and door openings of the cars characterized by: means disposed at a single floor, such as at the lobby, for entering destination calls;   means associated with the processor means for initiating an up-peak service mode;   means associated with the processor means for assigning priority levels to the cars in the up-peak service mode;   means associated with the processor means for determining a maximum number of destination calls to be assigned to a car in the up-peak service mode;   means associated with the processor means for assigning the maximum number of destination calls to the cars in order of their priority level in the up-peak service mode; and   means disposed in the lobby for indicating to passengers the destination calls that have been assigned to each car.   
     
     
       2. Apparatus according to claim 1, characterized in that: the maximum number of destination calls to be assigned to a car is determined as the number of floors above the lobby divided by the number of cars in service.   
     
     
       3. Apparatus according to claim 1 characterized in that: a. cars at the lobby with their doors open are assigned the highest priority level;   b. cars at the lobby with their doors closed are assigned a lower priority level;   c. cars headed toward the lobby having the lobby as their next stop are assigned a yet lower priority level; and   d. the car headed towards the lobby with the soonest predicted arrival time is assigned the lowest priority level.   
     
     
       4. Apparatus according to claim 3 characterized in that the predicted arrival time for a car running toward the lobby not having the lobby as its next stop is based on the number of floors the car is away from the lobby plus the number of calls ahead of the car plus a weighting factor for a call being serviced. 
     
     
       5. Apparatus according to claim 4 characterized in that the weighting factor is: a. a first value if the car is running with a stop command and its door closed;   b. a second value, lower than the first value, if the car is stopped with its doors just opening;   c. a third value, lower than the second value, if the car is stopped with its doors open and no start command;   d. a fourth value, lower than the third value, if the car is stopped with its doors closing and a start command;   e. a fifth value, lower than the fourth value, if the car is stopped with the doors closed and a start command; and   f. a sixth value, lower than the fifth value, if the car is just beginning to run.   
     
     
       6. Apparatus according to claim 3 characterized in that: calls initially assigned to a nonlobby car are reassigned to a lobby car having its doors open in the event that there is a car at the lobby with its doors open and able to accept calls, thereby eliminating frustration among waiting passengers whose calls were assigned to the car not at the lobby.   
     
     
       7. Apparatus according to claim 1 characterized by: means for establishing a basic dispatch interval for the cars based on the maximum number of passengers permissible per car multiplied by the ratio of the total number of cars to the number of cars in service.   
     
     
       8. Apparatus according to claim 7 characterized by: means for adjusting the basic dispatch interval to an individualized dispatch interval for each car based on a car's presence at, or absence from the lobby at the time of its first call assignment(s), the number of calls assigned to it, and the estimated number of passengers on board the car at the lobby based on load measurement; and wherein a provision for a remaining minimum timed interval setting is made for the occurrence of each additional assigned call and for each additional passenger boarding the car.   
     
     
       9. Apparatus according to claim 1 characterized in that destination calls are assigned to cars without assigning the maximum number of calls to each car in order of their priority level when the up-peak mode of service is not initiated.